, Northern Outcrop - Central (Penwyllt to Penderyn)
map using leaflet map:
On the road from Pont Nedd-Fechan to Ystradfellte turn off on Gwaen Bryn-Bwch to the fenced road and go for 1.5 miles to Pont Cwm Pwll-y-rhyd, Cross the bridge and go downstream for 330m to the further end of the ancient river course, dropping down into the present gorge, the cave entrance in immediately on one's right.
Permission should be sought from Blaen Nedd Isaf farm.
The entrance is 5m wide and 3m high, oval well-scalloped and running parallel with the deserted gorge, with its ceiling at the level of the floor of the gorge to start. Only about 100m are available for non-divers, it is a wet cave. The water in it comes from Cwm Pwll-y-rhyd in flood plus sinks from the moor above, and water flows from it into the present gorge, firstly into Town Drain Cave and in high flood down the gorge as well. It has been dived to Cwm Pwll-y-rhyd.
T. Braithwaite 1936
SWCC Newsletter 33 p.9-11,1960. Grade 2.
SWCC Our Caves. 3, p.8,9.
Caves and Caving 1(3) (BSA, 1938), Braithwaite, T.A.J., pp.93-98,